TPR Diagnostic 6 - PS #30

[pm1]

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The initial speed of a projectile fired vertically upward from ground level can be calculated if which of the following can be measured?
I. Impact velocity
II. Maximum height
III. Flight time
A) I and II only
B) I and III only
C) II and III only
D) I, II, and III

Answer: D

When I encounter questions like these I always get confused.. Do I just pick the answers that are necessary and sufficient? Or all the ones that will give me the initial speed?

I chose C thinking that with maximum height and flight time is enough to give me initial velocity. From the equation dx = Vot + at^2/2 . I can see that with impact velocity I can also find initial speed from V = Vo + at. However, I go back to my original question: do I just pick all of the ones that will give me Vo or just enough that will get me to Vo?

I hope this question makes sense. .🙄

 

[chiddler]

i don't understand your question :-x

 

[MedPR]

In this case you pick all of them because the question doesn't say "only" or any other word that hints that they want the minimum number of things 🙂

 

[pm1]

Thank you!
Sorry guys it was kind of confusing. ;P